Yaneeve · December 14, 2018 17:38 · Dec 14, 2018
diff --git a/cps_no_curry.scala b/cps_no_curry.scala
@@ -0,0 +1,45 @@
+// https://en.wikibooks.org/wiki/Haskell/Continuation_passing_style#Passing_continuations
+
+def add(x: Int, y:Int): Int = x + y
+
+def addCps[R](x: Int, y: Int): ((Int => R) => R) = {
+  def lambda[K]: (Int => K) => K = {k: (Int => K) => k(add(x, y))}
+  lambda
+}
+
+def square(x: Int): Int = x * x 
+
+def squareCps[R](x: Int): ((Int => R) => R) = { 
+  def lambda[K]: (Int => K) => K = { k: (Int => K) => k(square(x)) }
+  lambda
+}
+
+def pythagoras(x: Int, y: Int): Int = add(square(x), square(y))
+
+def pythagorasCps[R](x: Int, y: Int): ((Int => R) => R) = {
+  def lambda[K]: (Int => K) => K = {k: (Int => K) =>
+    val `x^2`: (Int => K) => K = squareCps[K](x)
+    val `y^2`: (Int => K) => K = squareCps[K](y)
+
+    `x^2`{xSquared =>
+      `y^2`{ySquared =>
+        addCps[K](xSquared, ySquared)(k)
+      }
+    }
+  }
+  lambda
+}
+
+val sCps: (Int => Unit) => Unit = squareCps[Unit](2)
+sCps({a => println(a)})
+
+val aCps: (Int => Unit) => Unit = addCps[Unit](1, 2)
+aCps({a =>
+  val b = a*13
+  println(b)
+})
+
+val pCsp: (Int => Unit) => Unit = pythagorasCps[Unit](3, 4)
+pCsp(println)
+
+// https://scastie.scala-lang.org/Yaneeve/PIcmIoO6SJyJREjNezp8qg